Copper-based sliding material

US20110206939A1Active Publication Date: 2011-08-25DAIDO METAL CO LTD
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Patent Information

Authority / Receiving Office
US · United States
Current Assignee / Owner
Publication Date
2011-08-25

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Abstract

Provided is a copper-based sliding material including a steel back-metal layer and a Cu alloy layer. The Cu alloy layer contains, by mass %, 10 to 30% of Bi, 0.5 to 5% of an inorganic compound, and the balance being Cu and inevitable impurities. The Cu alloy layer may further contain 0.5 to 5% of Sn and/or at least one element selected from the group consisting of Ni, Fe, P and Ag in a total amount of 0.1 to 10%. The inorganic compound has an average particle size of 1 to 5 μm and a specific gravity of 70 to 130% relative to the specific gravity of Bi. Bi phase is formed in the Cu alloy layer in an average particle size of 2 to 15 μm, and the Bi phase is dispersed in the Cu alloy layer and isotropic.
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Description

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a copper-based sliding material having excellent fatigue resistance, and in particular a copper-based sliding material suitable for a sliding bearing material used in an internal combustion engine.BACKGROUND OF THE INVENTION

[0002] Conventionally, a copper-based sliding material for use in a sliding bearing for an internal combustion engine has been generally manufactured by a continuous sintering process. In the continuous sintering process, a Cu alloy powder is continuously scattered onto a steel strip and then sintered and rolled in series. The copper-based sliding material for a sliding bearing has been required to be free of lead (Pb) in order to meet recent environmental restrictions, and thus a sintered Cu alloy containing bismuth (Bi) in place of Pb has been proposed (see, for example, JP-B2-3421724, JP-A-2005-200703, JP-A-04-28836 and JP-A-05-263166).

[0003] A crankshaft of an internal combustion engine tend...

Examples

examples

[0047]Examples 1 to 18 of a Bi-containing Cu alloy according to an embodiment of the invention, and Comparative Examples 21 to 30 were measured with the average particle size of a Bi phase and subjected to a bearing fatigue test. Table 1 shows compositions of Examples 1 to 18 and Comparative Examples 21 to 30. As for Examples 1 to 18, a Cu alloy powder was produced by an atomizing process and mixed with an inorganic compound with use of a general mixer. In this way, the inorganic compound was embedded in the Bi phase on a surface of the Cu alloy powder particle so as to satisfy the component ratio in Table 1. Subsequently, the powder mixture was scattered onto a steel strip and subjected to repeated sintering and rolling processes to produce a sliding material. The sintering was performed at a temperature of 850° C. The sliding material was formed into a semi-cylindrical shape to produce a sliding bearing.

TABLE 1ContentInorganic compoundInorganiccompoundspecificBi phase ingravity / Bi...